JP7271266B2 - Control device - Google Patents

Description

The present invention relates to a control device that controls driving of a motor.

In a control device that drives a motor, if the drive current of the motor contains a vibration component, unnecessary vibration occurs. Therefore, it is desirable to remove the vibration component from the drive current of the motor. In order to suppress vibration, non-interfering control is sometimes used to control the drive current of the motor.

Further, in motor drive control, a limiter may be provided to limit the torque command value so as not to exceed the upper limit torque value in order to protect the motor, inverter, and the like. Therefore, depending on the torque command value, the vibration suppression signal added to the torque command value by the non-interference control may be limited by the limiter, and the vibration suppression effect may be reduced. For example, in the technique disclosed in Patent Document 1, when the torque command value is limited, the characteristics of a limiter that limits the torque command value are changed according to the vehicle characteristics in order to effectively suppress the vibration of the vehicle. ing.

JP 2005-269836 A

However, in the technique disclosed in Patent Document 1, the characteristics of the limiter are changed for each vehicle, so there is a problem that the calculation becomes complicated and the processing load increases. Further, when the torque command is limited by a simple limiter, there is a problem that the damping suppression effect is lowered.

SUMMARY OF THE INVENTION In view of the above-described problems, an object of the present invention is to provide a control device capable of preventing deterioration of the effect of suppressing vibration in motor drive control using a limiter having a simple configuration.

In order to solve the above problems, according to one aspect of the control device of the present invention, the control device includes an angle detection section, a feedback section, a torque command calculation section, a limit section, a drive control section, a correction section, And prepare. The angular velocity detector detects the angular velocity of the motor. A feedback value is obtained from the angular velocity detected by the feedback section and the angular velocity detection section. The torque command calculation section obtains a torque command value according to a superior torque command value supplied from a host device and a feedback value obtained by the feedback section. The limiting section limits the torque command value obtained by the torque command calculating section so as not to exceed a predetermined torque upper limit value. The drive control section performs drive control of the motor according to the torque command value limited by the limit section. The correction section corrects the upper torque command value or the torque command value according to the feedback value obtained by the feedback section and the upper torque command value.

According to the present invention having the above configuration, it is possible to prevent deterioration of the effect of suppressing vibration in motor drive control using a limiter with a simple configuration.

1 is a block diagram showing a configuration example of a motor control system according to Embodiment 1; FIG. FIG. 2 is a block diagram showing a configuration example of a motor control unit that configures the motor control system; 3 is a block diagram showing a configuration example of a correction unit that constitutes a motor control unit; FIG. 7 is a flow chart showing an example of a calculation process for determining whether or not there is overtorque in a correction unit; FIG. 5 is a diagram showing an example of correction amounts generated by a correction unit; It is a figure which shows the example of the torque command value correct|amended by the correction|amendment part. FIG. 5 is a diagram showing an example of a state in which a torque command value is restricted by a limiter; FIG. 4 is a diagram showing an example of acceleration of a load driven by a motor due to vibration; FIG. 4 is a diagram showing an example of acceleration of a load driven by a motor due to vibration; FIG. 7 is a block diagram showing a configuration example of a motor control system according to a second embodiment; FIG. FIG. 10 is a diagram showing another example of correction amounts generated by the correction unit; FIG. 10 is a diagram showing another example of correction amounts generated by the correction unit;

Embodiments for carrying out the present invention will be described in detail below with reference to the accompanying drawings.
<Embodiment 1>
FIG. 1 is a block diagram showing a configuration example of a motor control system using a control device according to Embodiment 1 of the present invention.
This motor control system includes a motor 2 to be controlled that drives a load 1, a host device 3 that generates a high-order torque command value for the motor 2, a high-order torque command value _Tm from the host device 3, and the state of the motor 2. and a power conversion unit 5 for supplying the motor 2 with a drive current according to the control of the motor control unit 4 .

The motor 2 drives an electric vehicle, for example, and is composed of, for example, a three-phase brushless motor. In the case of an electric vehicle, for example, the host device 3 is composed of a VCU (Vehicle Control Unit) or the like that generates a host torque command value according to the degree of opening of the accelerator or the current vehicle speed. Note that the motor 2 may be a motor or the like that drives an arm of a robot or the like. Alternatively, the motor 2 may be composed of another motor such as a brushed DC motor. The power converter 5 is composed of, for example, an inverter, and performs switching of the power supply voltage according to the current control from the motor controller 4 to supply it to the motor 2 .

FIG. 2 is a block diagram showing a configuration example of the motor control section 4. As shown in FIG.
The motor 2 includes a field coil that generates a magnetic field according to the drive current supplied from the power converter 5, a permanent magnet attached to the rotor, etc., and generates a driving force according to the magnetic field generated by the field coil. do. The motor 2 also includes a position detector 2A and the like for detecting the position (angle) of the rotor.

The motor control unit 4 includes a feedforward unit 10 that obtains a feedforward torque command value _TmFF corresponding to the upper torque command value _Tm from the host device 3, and an angular velocity _ωm of the motor 2 from the detection output of the position detection unit 2A. A feedback unit 30 for obtaining a feedback torque command value _TmFB corresponding to the angular velocity _ωm of the motor 2, and a calculation unit 40 for obtaining a torque command value _Tmres are provided. The motor control unit 4 also includes a limiter 50 that limits the torque command value _Tmres from the calculation unit 40 so that it does not exceed a predetermined threshold value, and a drive current that is supplied to the motor 2 according to the torque command value _Tmres . It has a current control section 60 that performs control and a correction section 70 that corrects the higher-order torque command value _Tm from the higher-order device 3 .

In this motor control system, based on the torque command value _Tmres obtained from the feedforward torque command value (feedforward value) _TmFF from the feedforward section 10 and the feedback torque command value (feedback value) _TmFB from the feedback section 30, Non-interfering control for suppressing vibration of the motor 2 is performed by performing control by the current control unit 60 using the current control unit 60 .

The limiter 50 limits the torque command value T _mres from the calculation unit 40 so as not to exceed a predetermined threshold value T _lim and supplies it to the current command calculation unit 61 . This threshold value T _lim is, for example, the upper limit torque value of the motor 2 . Alternatively, the threshold T _lim may be set using, for example, the upper limit torque value and upper limit current value of the motor 2 .

The current control unit 60 includes a current command calculation unit 61 that obtains a current command value i _g according to the torque command value T _{mres_limit} supplied via the limiter 50 and the angular velocity ω _m of the motor 2 obtained by the speed calculation unit 20; A current control calculation section 62 is provided for controlling the driving current for driving the motor 2 according to the current command value i _g and the angular velocity ω _m of the motor 2 obtained by the speed calculation section 20 . The current control calculation unit 62 performs PWM (Pulse Width Modulation) control of the drive current by controlling the power conversion unit 5 according to the current command value _ig , for example.

In the motor control system configured as described above, when the host torque command value T _m is supplied from the host device 3 , the motor control unit 4 operates according to the host torque command value T _m and the angular velocity ω _m of the motor 2 . It controls driving of the motor 2 . Specifically, the correction unit 70 corrects the upper torque command value _Tm supplied from the host device 3 at predetermined time intervals, and supplies the corrected upper torque command value Tm _' to the feedforward unit 10. do. This correction is performed as necessary so as not to exceed the threshold value of the torque command value _Tmres limiter 50, as will be described later. The feedforward unit 10 obtains a feedforward torque command value TmFF corresponding to the upper torque command value Tm _′ , and supplies the feedforward torque command value _TmFF to the calculation unit 40 . The speed calculation unit 20 obtains the angular speed _ωm of the motor 2 from the detection output of the position detection unit 2A, and supplies it to the feedback unit 30 and the like. The feedback unit 30 obtains a feedback torque command value T _mFB from the angular velocity ω _m of the motor 2 and supplies it to the calculation unit 40 . The calculation unit 40 supplies the sum of the feedforward torque command value _TmFF and the feedback torque command value _TmFB to the limiter 50 as the torque command value _Tmres . The limiter 50 limits the torque command value T _mres not to exceed a predetermined threshold, and supplies it to the current command calculation unit 61 as the torque command value T _{mres_limit} .

Current command calculation unit 61 obtains current command value ig from torque command value _{Tmres_limit} supplied via limiter 50, angular velocity _ωm from speed calculation unit 20, _and power supply voltage value _VDC . supply to The current control calculator 62 controls the power converter 5 according to the current command value _ig supplied from the current command calculator 61 . Specifically, the current control calculation unit 62 calculates the current value _ir of the current supplied to the power conversion unit 5, the current command value _ig from the current command calculation unit 61, and the angular velocity _ωm from the speed calculation unit 20. Accordingly, the timing of switching by the power converter 5 is controlled. As a result, drive control according to the upper torque command value T _m from the upper apparatus 3 and the angular velocity ω _m of the motor 2 is executed.

FIG. 3 is a block diagram showing a configuration example of the correction unit 70. As shown in FIG.
The correction unit 70 includes a calculation unit 71 that performs calculations according to the upper torque command value _Tm and the feedback torque command value _TmFB from the host device 3, and an overtorque calculation unit 72 that calculates whether or not there is overtorque. , a noise reduction unit 73 that reduces the gain of noise included in the calculation result of the overtorque calculation unit 72, and a maximum value calculation unit 74 that calculates the maximum value for selecting the correction amount ΔT. The noise reduction section 73 is composed of, for example, a low-pass filter. The correction unit 70 also includes a previous value holding unit 75 that holds the correction value of the previous processing, an attenuation unit 76 that holds the value held in the previous value holding unit 75, and determines the sign of the correction amount. It has a sign determination section 77 and a calculation section 78 that corrects the upper torque command value _Tm according to the correction amount ΔT. Note that the calculation unit 78 may be configured as an addition unit that adds the correction amount ΔT to the upper torque command value _Tm .

FIG. 4 is a flow chart showing an example of calculation processing for determining whether or not there is overtorque by the overtorque calculation unit 72 of the correction unit 70 .
The overtorque computing section 72 executes the process of FIG. 4 at predetermined time intervals. In S1, the overtorque calculation unit 72 calculates the absolute value of the sum Tc of the upper torque command value _Tm supplied from the calculation unit 71 and the feedback _torque command value _TmFB and the threshold value _Tlim of the limiter 50. An absolute value comparison operation is performed to determine whether or not the absolute value of the sum _Tc exceeds the threshold _Tlim of the limiter 50 .

If the absolute value of the sum T _c exceeds the absolute value of the threshold T _lim of the limiter 50, the overtorque calculator 72 calculates the absolute value of the sum T _c and the absolute value of the threshold T _lim of the limiter 50 in step S2. The difference in values is supplied to the maximum value calculator 74 via the noise reducer 73 . On the other hand, if the absolute value of the sum T _c does not exceed the threshold value T _lim of the limiter 50 in step S1, the overtorque calculation unit 72 sets the value 0 to the maximum value calculation unit via the noise reduction unit 73 in step S3. 74. The above processing is repeated at predetermined time intervals.

The noise reduction unit 73 reduces the noise gain of the value supplied from the overtorque calculation unit 72 at predetermined time intervals, and supplies the noise gain to the maximum value calculation unit 74 . The previous value holding section 75 holds the output of the maximum value calculating section 74 during the previous processing. The attenuation unit 76 attenuates the output of the maximum value calculation unit 74 in the previous process and supplies the output to the maximum value calculation unit 74 . The processing by the attenuation unit 76 may subtract a constant value from the value stored in the previous value holding unit 75 . Alternatively, it may be attenuated by another method such as a first-order lag system.

The maximum value calculation unit 74 selects the value supplied from the overtorque calculation unit 72 via the noise reduction unit 73 and the output of the maximum value calculation unit 74 attenuated by the attenuation unit 76 during the previous process. output the larger one. This output is supplied to the sign determination section 77 and the previous value holding section 75 . The sign determination unit 77 determines the sign of the correction amount ΔT based on the sign of the input signal, and supplies the correction amount ΔT including the obtained sign to the calculation unit 78 . The calculation unit 78 corrects the upper torque command value T _m based on the supplied correction amount ΔT, and supplies the corrected torque command value T _{m ′} to the feedforward unit 10 .

FIG. 5 is a diagram showing an example of the correction amount ΔT generated by the correction unit through the correction process described above.
This correction amount ΔT increases during the period when the torque command value T _mres exceeds the threshold value T _lim of the limiter 50 when no correction is performed, and becomes a value that attenuates as time elapses. By correcting the upper torque command value _Tm using the correction amount ΔT obtained as described above, the torque command value _Tmres does not exceed the threshold value _Tlim of the limiter 50, as shown in FIG. . In this example, the sign determination unit 77 sets the sign of the correction amount ΔT to be negative, and the calculation unit 78 indicates the result of adding the correction amount ΔT, which is a negative value, to the upper torque value _Tm .

On the other hand, if the upper torque command value _Tm is not corrected, depending on the state of the upper torque command value _Tm and the feedback torque command value _TmFB , for example, as shown in FIG _. exceeds the threshold value _Tlim of the limiter 50, and the limiter 50 limits the value of the torque command value. As a result, the effect of suppressing vibration is reduced. In the present embodiment, as described above, by correcting the upper torque command value _Tm so that the torque command value _Tmres does not exceed the threshold value _Tlim of the limiter 50, the effect of suppressing vibration in motor drive control is improved. A decrease can be prevented.

FIGS. 8 and 9 compare examples of acceleration of the load 1 driven by the motor 2 due to vibration when the upper torque command value _Tm is not corrected and when the upper torque command value _Tm is corrected. is. 8 and 9 show an example of the acceleration of an electric vehicle, for example in the case of an electric vehicle. Reference numeral 81 in FIG. 8 and reference numeral 83 in FIG. 9 indicate acceleration due to vibration when the upper torque command value _Tm is not corrected, and reference numeral 82 in FIG. 8 and reference numeral 84 in FIG. It shows the acceleration due to vibration when _m is corrected. As is clear from the comparison between FIGS. 8 and 9, the correction of the upper torque command value _Tm by the correction unit 70 can prevent the reduction of the effect of suppressing vibration.

In addition, in the present embodiment, by correcting the upper torque command value _Tm as described above, it is possible to prevent a decrease in the effect of suppressing vibration in the drive control of a motor that limits the torque command value using a limiter with a simple configuration. can do. In addition, in the present embodiment, since vehicle characteristics are not used in the calculation of the correction amount by the correction unit 70, an increase in processing load can be suppressed. Therefore, according to the present embodiment, it is possible to prevent deterioration of the vibration suppression effect while suppressing an increase in the processing load.

<Embodiment 2>
FIG. 10 is a block diagram showing a configuration example of a motor control unit that constitutes the motor control system of the second embodiment. In the first embodiment, the correction unit 70 is configured to correct the upper torque command value _Tm from the host device 3, but in the present embodiment, the correction 90 corrects the feedforward torque command value _TmFF from the feedforward unit 10. is to be corrected.

Correction section 90 is configured _in the same manner as correction section 70 shown in _FIG . A correction amount ΔT is obtained to correct the feedforward torque command value _TmFF .

As described above, according to the present embodiment, by correcting the torque command value according to the upper torque command value and the feedback value obtained by the feedback unit, a simple configuration similar to that of the above-described first embodiment can be achieved. It is possible to prevent a decrease in the effect of suppressing vibration in motor drive control using the limiter.

<Modification>
In the above-described embodiment, an example using the correction amount ΔT shown in FIG. 5 has been described. However, as shown in FIG. 11, for example, a correction amount ΔT with a fast decay time may be used. Since the vibration suppression effect is high during the period when the value of the feedback torque command value _TmFB rises, the torque command value is corrected so as not to exceed the threshold value _Tlim of the limiter 50 during the period when the value of the feedback torque command value TmFB _rises . You can decide. In order to generate such a correction amount ΔT, for example, the attenuation amount by the attenuation section 76 of the correction section 70 should be increased.

Also, the correction amount ΔT may be a constant value. As a result, it is possible to maintain the vibration suppressing effect while further suppressing an increase in the processing load for correcting the torque command value. In this case, the corrected torque command value may be corrected so as not to exceed the threshold _{value Tlim} of the limiter 50, but for example, as shown in FIG. The correction amount ΔT may be obtained so that the range is equal to or less than a predetermined threshold. Even if the corrected torque command value exceeds the threshold value T _lim of the limiter 50 to some extent, the effect of suppressing the vibration is still obtained. It is possible to improve the responsiveness to the upper torque command value. It should be noted that the degree of correction to be performed by the correction unit may be determined by comprehensively considering, for example, the required vibration suppression effect, the magnitude of the processing load, the required responsiveness, and the like.

Further, in each of the above-described embodiments, an example in which the limiter 50 that limits the torque command value is provided has been described. The correction unit may correct the upper torque command value or the torque command value.

Each of the above-described embodiments is an example of means for realizing the present invention, and should be appropriately modified or changed according to the configuration of the device or system to which the present invention is applied and various conditions. The form is not limited.

DESCRIPTION OF SYMBOLS 1... Load 2... Motor 2A... Position detection part 3... Host device 4... Motor control part 5... Power conversion part 10... Feed forward part 20... Velocity calculation part 30... Feedback part 40... Calculation unit 50 Limiter 60 Current control unit 61 Current command calculation unit 62 Current control calculation unit 70 Correction unit 80 Correction unit

Claims (5)

an angular velocity detector that detects the angular velocity of the motor;
a feedback unit that obtains a feedback value from the angular velocity detected by the angular velocity detection unit;
a torque command calculation unit that obtains a torque command value according to a superior torque command value supplied from a superior device and a feedback value obtained by the feedback unit;
a limiting unit that limits the torque command value obtained by the torque command calculating unit so that it does not exceed a predetermined torque upper limit value;
a drive control unit that controls the drive of the motor according to the torque command value limited by the limiter;
a correction unit that corrects the upper torque command value or the torque command value for each control cycle of the drive current that drives the motor, according to the feedback value obtained by the feedback unit and the upper torque command value;
A control device comprising: A feedforward unit that obtains a feedforward value according to the upper torque command value,
2. The control device according to claim 1, wherein the torque command calculation unit obtains the torque command value according to the feedforward value obtained by the feedforward unit and the feedback value obtained by the feedback unit. . The correction unit is
performing correction so that the torque command value after correction does not exceed a predetermined threshold;
3. The control device according to claim 1 or 2, characterized in that: The correction unit is
Based on the upper torque command value and the feedback value obtained by the feedback unit,
a detection unit that detects whether or not the torque command value exceeds the predetermined threshold;
a maximum value calculation unit that calculates the maximum value of the torque command value when the detection unit detects that the torque command value exceeds the predetermined threshold;
a correction amount calculation unit that calculates a correction amount according to the maximum value of the torque command value obtained by the maximum value calculation unit;
a correction processing unit that corrects the upper torque command value or the torque command value according to the correction amount obtained by the correction amount calculation unit;
4. The control device of claim 3, comprising: an angular velocity detector that detects the angular velocity of the motor;
a feedback unit that obtains a feedback value from the angular velocity detected by the angular velocity detection unit;
a torque command calculation unit that obtains a torque command value according to a superior torque command value supplied from a superior device and a feedback value obtained by the feedback unit;
a drive control unit that controls the drive of the motor according to the torque command value;
a correction unit that corrects the upper torque command value or the torque command value for each control cycle of the drive current that drives the motor, according to the feedback value obtained by the feedback unit and the upper torque command value. ,
The correction unit is
performing correction so that the torque command value after correction does not exceed a predetermined threshold;
A control device characterized by:

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